Answer:
1.8181818181818181818181818181818
Answer:
a = 7
Step-by-step explanation:
3(1 - 2a) = -3a - 18
3 - 6a = - 3a - 18
Add 18 to each side:
3 + 18 - 6a = - 3a - 18 + 18
21 - 6a = - 3a
Add 6a to each side:
21 - 6a + 6a = - 3a + 6a
21 = 3a
3a = 21
Divide each side by 3:
3a ÷ 3 = 21 ÷ 3
a = 7
30. is 8 [-5] [3] [-2] -2
Answer:
-3
Step-by-step explanation:

Another way is to note that there are <span><span>(<span>104</span>)</span><span>(<span>104</span>)</span></span> (“10 choose 4”) ways to select 4 balls from a collection of 10. If 4 of those 10 balls are “special” in some way (in this case, “special” = “red”), then the number of ways to choose 4 special balls is <span><span>(<span>44</span>)</span><span>(<span>44</span>)</span></span>. (The factor of <span><span>(<span>60</span>)</span><span>(<span>60</span>)</span></span> is included to convey that, after choosing 4 special balls, we choose none of the 6 non-special balls.) This line of reasoning gives the second expression.